1. Field of the Invention
The present invention relates to a phase shifter and a phase shift method.
2. Description of the Related Art
A phase shifter alters the phase of an AC voltage or an AC current. Phase shifters are utilized in a wide range of applications. For instance, a phase shifter in a portable telephone converts the phase of a electromagnetic wave transmitted from a base station so as to improve the reception sensitivity with which the electromagnetic wave transmitted from the base station is received.
To respond to the broad demand, various types of phase shifters, some using analog signals and others using digital signals, are being developed.
Technologies related to phase shifters that use analog signals include that disclosed in patent reference literature 1. Technologies related to phase shifters that use digital signals include that disclosed in patent reference literature 2.    (Patent Reference Literature 1) UK Patent Specification No. 1527603    (Patent Reference Literature 2) Japanese Laid Open Patent Publication No. H10-150363